A picket boat is a type of small naval craft. These are used for harbor patrol and other close inshore work, and have often been carried by larger warships as a ship's boat. They are usually 30 to 55 feet long.
Patrol boats, or any craft engaged in sentinel duty, are sometimes referred to as picket boats, using "picket" in the generic sense, even if much larger than actual picket boats. Picket boats were indeed at first steam pinnaces deployed to patrol anchorages to protect them from enemy torpedo boats, thus acquiring the new name "picket boat".[citation needed]